Prevention of venous thromboembolic events occurring in myeloma patients treated with second-generation novel agents.

Thrombosis and neoplasms are strictly linked, and the diagnosis of a malignancy is a relevant risk factor for venous thromboembolism (VTE). In particular, between gammopathies, the VTE risk is known to be increased in both monoclonal gammopathy of uncertain significance and in multiple myeloma, with a 3- and 9-fold increase respectively, when compared to the general population. The risk appears to be further increased in patients treated with immunomodulating drugs, such as thalidomide, especially when in combination with dexamethasone or conventional cytotoxic chemotherapies, and lenalidomide. In 2008 the International Myeloma Working Group put out thrombosis prophylaxis recommendations for myeloma patients treated with IMiDs. Current recommendations for thromboprophylaxis suggest the use of low-dose acetylsalicylic acid in patients with low risk for thrombosis and therapeutic dose anticoagulation with LMWH or warfarin for high-risk patients. However, these recommendations have been frequently not followed in the clinical practice, due to various reasons that involve the patients' will, the level of evidence of the recommendations and some selection biases in the studies that were taken as basis for writing down the indications. The new direct oral anticoagulants have been preliminarily evaluated for the prophylaxis of thrombotic events in IMiDs-treated myelomas, being promising, even if more expensive. Currently, the most reliable tool for a correct thrombotic risk stratification appears to be the complete clinical and anamnestic evaluation of the myeloma patients added to a strong physician awareness of the evidences that the literature contains until now.